不同裂性葡萄品种果皮结构及代谢物质差异分析

Analysis of Histological Structure and Cell Wall Metabolites in Different Cracking Grape Varieties

【目的】研究不同葡萄品种从转色期至成熟期裂果特性的调控因子,为易裂果品种在新疆高效栽培提供数据支撑。【方法】以红地球、里扎玛特、新郁、无核紫、木纳格5个葡萄品种为材料,在转色期至成熟期,测定细胞壁结构性物质水溶性果胶、原果胶、半纤维素含量及代谢水解酶PG、PEP、PL、CE活性,分析采收期细胞壁结构及细胞凋亡情况,研究细胞壁组成成分和细胞凋亡与裂果之间的关系。【结果】红地球为不易裂果品种,里扎玛特为极易裂果品种,其他3个品种为易裂果品种。红地球原果胶采收期含量最高,花后80~90 d原果胶含量增幅最高达到31.6%,里扎玛特的增幅最小为1.1%;花后70~90 d新郁和里扎玛特水溶性果胶含量增幅分别为80.8%和67.2%,红地球水溶性果胶增幅最低,增幅为26.1%,采收期果胶裂解酶酶活性下降;花后80~90 d里扎玛特半纤维素含量显著升高,增幅为134.7%,红地球成熟期含量下降,增幅为-5.9%。里扎玛特角质层不平整有断口与缺链,表皮细胞排列松散细胞间有间隙;新郁亚细胞间由于胞间质降解出现空腔;红地球角质层平整光滑,细胞排列整齐,细胞间无明显间隙。采收期里扎玛特细胞凋亡现象严重,新郁、木纳格、无核紫有不同程度凋亡现象,红地球无明显凋亡现象。【结论】随着采收时间的推移,不易裂果品种原果胶含量及增速显著高于易裂品种,水溶性果胶和半纤维素含量变化规律相反;这3个指标与裂果相关。随着果实的成熟易裂品种在细胞壁代谢相关酶的作用下降解细胞壁结构多糖,果胶转化为水溶性果胶,纤维素转化为半纤维素,致使角质层不平整出现断口与缺链,细胞出现凋亡,降低了果皮的强度及细胞壁的延伸性,诱导了裂果发生。

【Objective】To explore the regulation factors of grape cracking characteristics of different varieties from the verasion period to the maturity stage,and provide data support for the efficient cultivation of easy cracking fruit varieties in Xinjiang.【Methods】From the verasion period to the mature period,five varieties were taken as the research objects,through the structural substances of the cell wall,water-soluble pectin,propectin,hemicellulose content and metabolic hydrolase PG,PEP,PL and CE enzyme activity were measured and analyzed and finally cell wall structure observation and TUNEL cell apoptosis detection were combined to explore the relationship between cell wall composition and cell apoptosis of fruit cracking.【Results】80 to 90 days after flowering,the increase in the propectin content Rizamat was 1.1,Red Globe was 31.6,respectively,the Red Globe had the highest increase and the harvest time content was the highest among the five varieties.70 to 90 days after flowering,the increase in the water-soluble pectin content was 80.8,67.2%of Xinyu and Rizamat.The Red Globe had the lowest increase 26.1%and the harvest time content was lowest.The activity of pectatelyases of Red Globe decreased.The hemicellulose content of Rizamat increased significantly at maturity,80 to 90 days after flowering,the increase was 134.7%,the content of Red Globe decreased and had the lowest increase-5.9%.The results of cell structure showed that Rizamat cuticle was uneven with fracture and chain missing,and epidermal cells were loosely arranged with intercellular space.Cavity appeared between subcellular of Xinyu.The stratum corneum of Red Globe was even and smooth,the cells were arranged orderly,and there was no obvious space between the cells.The TUNEL test showed that the programmed cell death was different,the Rizamat was serious during the harvest period,Xinyu,Munake and Black Monukka was milder,but no obvious finding was found in Red Globe.【Conclusion】During the ripening process of grape fruits,the content and growth rate of the propectin of the non-cracking varieties were significantly higher than easily cracking varieties.The content and growth rate of the water-soluble pectin and hemicelluloses were opposite.As the fruit matures,the easily cracking varieties cell wall structural polysaccharides under the action of enzymes related to cell wall metabolism,propectin is converted into water-soluble pectin,and cellulose is converted into hemicellulose,resulting in uneven surface with fracture and chain missing,and epidermal cells were loosely arranged with intercellular space,and programmed cell death are obvious,which reduces the strength of the peel and the extensibility of the cell wall,and in turn induces the occurrence of fruit cracking.